Q189998: BUG: Data Environment: MSHFlexGrid Rebinding Data

Article: Q189998
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:6.0
Operating System(s): 
Keyword(s): kbGrpDSVBDB
Last Modified: 09-JAN-2000

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The information in this article applies to:

- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
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SYMPTOMS
========

Attempting to rebind the MSHFlexGrid to a different Data Environment as the
DataSource property results in an error:

  Runtime Error 30022, The Hierarchical FlexGrid does not support the requested
  type of data binding.

CAUSE
=====

If the MSHFlexGrid.DataMember is set to a Data Environment other than the
original, the MSHFlexGrid attempts to rebind the data using the previous
DataSource property setting. Because the same Command does not exist in the
subsequent Data Environment, an error results.

RESOLUTION
==========

To work around this problem, set MSHFlexGrid.DataSource = Nothing before
rebinding to the next Data Environment.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. We are researching this bug and will post new
information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION
================

1. Create a new Visual Basic Standard.Exe project.Form1 is created by default.

2. From the <Project-Components-Controls> menu, check the selection for
  <Microsoft Hierarchical FlexGrid Control 6.0 (OLEDB)>.

3. Add a MSHFlexGrid to the form.

4. From the <Project-Add Data Environment> menu, create a new Data
  Environment.

5. Right-click the Connection icon and, under the Provider tab, select
  <Microsoft Jet OLEDB Provider>. On the Connection tab, click the
  ellipse button, choose the NWind.MDB, and then click OK.

6. Right-click the Connection icon again, and select <Add Command>.

7. Right-click on Command, and select <Properties>. Select <Table>
  as the database object source, and select <Employees> for the Object
  Name.

8. Right-click the Command icon and select <Rename>. Rename the Command to
  <test1>.

9. Repeat steps 4-7 to create a second Data Environment. Do not rename the
  second Command.

10. Add two CommandButtons to the form and paste the following code into each
  respectively.

        Private Sub Command1_Click()
           'Set MSHFlexGrid1.DataSource = Nothing
           MSHFlexGrid1.DataMember = "test1"
           Set MSHFlexGrid1.DataSource = DataEnvironment1
        End Sub

        Private Sub Command2_Click()
           'Set MSHFlexGrid1.DataSource = Nothing
           MSHFlexGrid1.DataMember = "command1"
           Set MSHFlexGrid1.DataSource = DataEnvironment2
        End Sub

11. Run the project and click on ommand1. The MSHFlexGrid should be populate
  with the results. Click on Command2. You should receive an error
  indicating:

  The Hierarchical FlexGrid does not support the requested type of data
  binding.

12. Uncomment the commented out lines in the CommandButtons. Repeat step 11. You
  should not receive an error attempting to rebind the Data Environment.

REFERENCES
==========

Visual Basic Books Online, "The Data Environment"

Additional query words: kbVBp600bug kbDSupport kbdse kbDatabase kbVBp kbDataBinding kbCtrl

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Keywords          : kbGrpDSVBDB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600
Version           : WINDOWS:6.0
Issue type        : kbbug

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